This invention relates in general to a novel system for connecting to tanks plastic tank linings having preformed shapes to surround flanges, fittings and other penetrations through the tank wall.
It is well-known that metal tanks, vessels and the like are subject to corrosion and other problems over extended periods of use. Tanks, such as in water conditioning, have had liners comprising (1) a painted interior; (2) rubber that has been lined in situ for a complete rubber lining; or (3) a lining formed of a sheet vinyl material. Typically, when a water conditioning tank has many flanged openings and handholds, either the painted interior or the rubberized interior is used. The vinyl liner has been used only with vessels having a simple outlet. Normally, vinyl lining is fabricated from sheet material which is cut and formed to conform with the interior of the vessel. The seams are then sealed through any known technique, such as a radio frequency heat sealing technique, as disclosed in U.S. Pat. No. 3,159,306, or a solvent, or impulse sealing. The vinyl adheres by virtue of the near vacuum created between the liner and the vessel wall.
The irregularity of an opening, such as a manhole, is not suitably accommodated by sheet material liners without excessive wrinkling. In service, wrinkles in the tank liner are subject to damage and tearing where pressure is applied. Accordingly, the advantageous presence of a vinyl liner has not been feasible where the tank possesses numerous penetrations, as are commonly present.